Firearm safety



R. E. c LRKsoN FIREARU 'SAFETY June 4, 1957 Filed uw 24, 1954 June 4, 1957 v R, E. CLARKSON FIREARM SAFETY 5 SheetsSheet 2 Filed Nov. 24, 1954 Unite Stats arent FIREARM SAFETY Ralph E. Clarkson, Hamden, Conn., assigner to @lin Mathieson Chemical Corporation, New Haven, Conn., a corporation of Virginia Application November 24, 1954, Serial No. 470,901

22 Claims. (Cl. 432-17) This invention relates generally to firearms, and more particularly to semi-automatic or fully automatic firearms with recoil-operated breech blocks.

The firearm with which the present invention is concerned is of a well-known type having a chamber unit which is separate from the barrel and yieldable from its firing position into the receiver by recoil action to initiate release of the locked breech block from the chamber unit and retraction of the former into open position by recoil action of its operating mechanism. Exemplary of a firearm of this type is that shown and described in the patent to Williams No. 2,476,232, dated July I2, 1949. In this exemplary firearm, the breech block is by its operating mechanism normally urged forwardly into closed position in which the same is interlocked with the chamber unit in its firing position and bears against a stop surface in the receiver. Release of the breech block from interlock with the chamber unit and retraction of the former into its open position for reloading purposes is achieved, after short recoil of the chamber unit with the interlocked breech block, by recoil action of the operating mechanism of the latter. To this end, the operating mechanism includes a link having with the breech block a cam-type lost-motion connection which is arranged so as immediately to impart the recoil of the chamber unit and interlocked breech block to the operating mechanism so that the latter will, at the end of the recoil of the chamber unit, have sufficient inertia to cause, by the cam action of its lost-motion connection with the breech block, release of the latter from interlock with the chamber unit and then its retraction into fully open position. The barrel, while normally mounted on the receiver, is nevertheless readily removable therefrom, thereby not only facilitating the assembly of the firearm and its occasional disassembly for the cleaning, repair or replacement of any part or parts thereof, but also conforming to the established custom of providing firearms of this type with removable barrels for their shipment and personal carriage during non-use in disassembled fashion.

It is the principal object of the present invention to provide a firearm of the movable chamber type, having a removable barrel, with safety means operable by said removable barrel to render the gun positively incapable of being fired.

More specifically, it is an object of the present invention to provide a firearm of this type which through the action of the removable barrel may not be fired unless the barrel is mounted in its place in the receiver.

Another object of the present invention is to provide a firearm of this type which no longer may be fired when its barrel is removed, by using the breech block as an automatic safety which is rendered operative when the barrel is removed and inoperative when the barrel is remounted.

A further object of the present invention is to provide a firearm of this type in which the aforementioned automatic safety feature prevents the tiring of a cartridge Patented .lune 4, 1957 which may have been chambered before the removal of the barrel, even though the latter is thereafter removed. This is achieved by arranging the breech block and chamber unit so that the former in its normal closed or locked position and the latter in its normal firing position are held by the mounted barrel slightly retracted in the receiver from fully advanced or safety position. In this normal firing position, the breech block and its associated operating mechanism are coordinated with the tire control mechanism so that, on actuation of the trigger, the hammer is released and will strike the firing pin in the breech block and fire a chambered cartridge. However, upon removal of the barrel, the breech block and chamber unit are urged forward from their aforesaid normal positions into the aforesaid fully advanced or safety position, and in such position the arrangement is such that the hammer will be stopped by positive means short of the firing pin and will therefore fail to fire a chambered cartridge.

It is another object of the present invention to provide a firearm of this type in which the aforementioned automatic safety feature is achieved, to prevent firing of a cartridge chambered after the removal of the barrel, by the aforementioned forward motion of the chamber unit into its safety position in consequence -of the removal of the barrel, whereby the aforementioned cam action of the lost-motion connection between the breech block and the link of its operating mechanism causes the breech block to become jammed against and stopped by, instead of interlocked with, the chamber unit in its safety position, with the result that by virtue of the aforementioned coordination of the breech block and its operating mechanism with the fire-control mechanism, the trigger-released hammer will be stopped short of the firing pin in the breech block and, hence, fail to fire the chambered cartridge.

Further objects and advantages will appear to those skilled in the art from the following, considered in conjunction With the accompanying drawings.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. l is a fragmentary view, partly in longitudinal section and partly in elevation, of a firearm embodying the present invention;

Fig. 2 is a fragmentary longitudinal section through the firearm at the moment of firing;

Figs. 3 and 4 are cross-sections through the firearm as taken on the lines 3-3 and 4--4, respectively, of Fig. l;

Fig. 5 is a fragmentary longitudinal section through a part of the firearm;

Fig. 6 is a fragmentary side view of the firearm with its barrel removed;

Fig. 7 is a fragmentary longitudinal section through the firearm with its barrel removed and demonstrating a safety feature which prevents firing of the arm while its barrel is removed; and

Fig. 8 is another fragmentary longitudinal section through the firearm with its barrel removed and demonstrating another safety feature which prevents firing of the arm while the barrel is removed.

Referring to the drawings, and more particularly to Figs. l and 2 thereof, the reference numeral 1) designates an exemplary firearm which in all essential respects is like that shown and described in the aforementioned patent to Williams, No. 2,476,232, or in the patent to Williams, No. 2,506,982, dated May 9, 1950. Thus, the instant firearm 10 comprises a receiver 12, a barrel 14, a chamber unit 16, a breech block 18, breech block operating mechanism 20, and fire control mechanism 22. Suitably secured to the rear end of the receiver 12 is a buttstock 24, and removably mounted as at 26 in the front wall 28 of the receiver is the barrel 14. The receiver 12 is recessed at 38 over most of its length, and is open at its bottom as at 32 and provided with an internal shoulder intermediate the length of the recess 3l): Guided for axial movement in a partecylindrical forward length 36 of the recess 30 in the receiver 12 is a part.- tubular rearward extension '38 of the chamber unit k16 (Figs. 1 to 3) having a chamber 46 which extends into the mounted barrel 14 and is adapted for the reception of a cartridge c to be tired. The chamber unit 1'6'l is normally urged forwardly into abutting engagement with the mounted barrel 14 by a spring-urged plunger 42 which is received by the rearward extension 38 of the chamber unit and bears against the internal shoulder 34 in .the

recessed receiver 12. e

nThe breech block 18 is at its topV semi-cylindricalin cross-section (Fig. 3) for tted reception in the part-tulnt lar rearward extension 38 of the chamber unit 16'when the breech block is in' its closed position in which the sameis interlocked with the chamber unit 16 and engages the chambered cartridge c (Figs. l and 2). The breech block 18 is reciprocable in the recessed receiver 12 into its open and closed'positions, and is to this end connected, in floating pivotal fashion for a purpose described here= inafter, with a pin 46 which is carried by opposite guides 48 and Si? received in Ways 52 and 54, respectively, which extend longitudinally of the receiver and may appropriately be machined in the opposite side walls 56 and 58, respectively, of the latter (Fig. 3).

The breech block operating mechanism 20, which in the instant exemplary firearm is recoil-operated for releasingV the breech block 18 from interlock with the chamber unit 16 and retracting the former into its open position for reloading purposes, comprises an inertia bar or plun-` ger 60 which at its rear is backed by a pre-loaded com-V pression-type spring 62 (Fig. 5) and is at its forward end pivotally connected at 64 with one end of a link 66 that extends with its other end into a bottom recess 68 in the breech block 18 and is pivotally connected with the pin 46 (Figs. 2 and 3). The inertia bar 60 is axially slidable in a guide sleeve 70 (Figs. 2 and 5) which extends in the buttstock 24 and carries at its forward end a threaded collar 72 by means of which it is mounted in the rear of the receiver 12. The rear end of the guide sleeve 70 is connected, in this instance threadedly as at 74 (Fig. 5), with the adjacent forward end of another sleeve 76 in the buttstock 24 which holds the compression spring 62 that serves to close the breech block. The rear end (not shown) of the sleeve 76 is closed and the adjacent end of the spring 62 bears thereagainst, while the opposite end of the latter bears against an end collar 78 on the inertia bar 60 and normally urges the latter forwardly in the direction of the arrows 80 in Figs. 5 and 2 so as to force the breech block 18 into its closed position through ntermediation of the link 66. The aforementioned floating pivotal or lost-motion connection between the pin 46 and the breech block 18 is obtained by identical slots 82 in the opposite sidewalls 84 of the latter through which the pin 46 extends (Figs. 1 to 3). The slots 82 have forward lengths 86 which extend parallel to the longitudinal axis of the breech block 18, and rearwardly continuing cam lengths 88 which are inclined to this axis. For the interlock of the breech block 18 in its closed position with the chamber unit 16, the breech block has at its top a key formation 90 'and the rearward extension 38 of the chamber unitl 16 is provided with a longitudinal slot 92 the endwall 94 'of which serves as a lock shoulder for the key formation 90 4of the breech block.

After tiring the chambered cartridge c, in a manner explained hereinafter, `while the beech block 18 is in its closed position and interlocked withthe chamberunit 16 (Fig. 2), the ensuing full recoil force of the shell of the fired cartridge will instantaneously be imparted to the breech block 18 and also to the chamber unit 1,6 by virtue of the interlock of the latter with the former, with' the result that both are thrown backwards until the rearward extension 38 of the chamber unit engages the internal stop shoulder 34 in the receiver 12. The recoil of the interlocked chamber unit 16 and breech block 18 is at its very inception also transmitted to the breech block operating mechanism 20 by virtue of the then prevailing engagement of the pin 46 with the ends 98 of the forward lengths 86 of the slots 82 in the breech block (Fig. 2), with the result that the link 66 and the inertia bar 60 are thrown backwards with a force of sufficient magnitude to compress the pre-loaded spring 62 (Fig. 5). The breech block operating mechanism 20, though resisted in its recoil by the spring 62 will nevertheless gain sudicient inertia to cause the rectilinearly travelling pin 46, after its traverse of the forward lengths 86 of the slots 82 in the breech block 18, to cooperate with the inclined cam lengths 88 of` these slots, first to tilt the breech block counterclockwise as viewed in Fig. 2 and thereby withdraw the key formation 90 of the latter from the locking shoulder 94 in the chamber unit 16 as the rearward extension 38 of the latter is still in engagement with the internal stop shoulder 34 in the receiver` 12,. and then to retract the released breech block to its fully open position. Due to the floating pivotal connection of the pin 46 with the breech block characteristicsof the rear lengths 88 of the slots 82 in the latter, and further due to the guidance of the pin 46 in a rectilinear pathby the side Vguides 48 and S0 in the ways 52 and 54 in the receiver (Fig. 3), the pin 46 and the inclined cam lengths 88 of the slots 82 in the breech block will, during the retraction of the latter into its fully open position, also cooperate to tilt the breech block suliiciently so that the same will readily be accommodated in the rearwardly and downwardly slanting part 100 of the recess 30 in the receiver, all as fully shown in the aforementioned patent to Williams. No. 2,506,982. As already mentioned, the spring 62, compressed as itis to a maximum extent when the breech block 18 is in its fully open position, will return the latter into its closed position (Figs. 1 and 2) through intermediation of the inertia bar 60 and link 66. The breech block 18 will during its entire forward motion be compelled, first by the top wall 102 of the rear part 100' of the recess 30 in the receiver and then by the top wall 104 of the rearward extension 38 of the chamber unit 16 (Fig. 2), to remain tilted about the pin 46 until the key formation 90 on the breech block interlocks with the shoulder 94 in the chamber unit 16 at the time the breech block reaches its closed position. Accordingly, the spring-urged forward motion of the inertia bar 60 and link 66 is transmitted to the breech block 18 by the pin 46 while the same cooperates with the' inclined cam lengths 88 of the slots 82 inthe breech block, and it is only after the breech block reaches its closed position and its key formation aligns with the slot 92Vin the chamber unit 16 that the inclined earn lengths 88 'of the slots 82 cooperate with the pin 46 to rock the breech block, clockwise as viewed in Fig. 2, into interlock with the vchamber' unit. After thus camming the breech block 18 into interlock with the chamber unit 16, the pin 46 reaches the forward lengths 86 of the slots 82 in the breech block and is moved forwardly therein by the spring-urged inertia bar 60 and link 66 until it cornes to bear against the ends 98 of the slot portions 86 and yieldingly holds the interlocked breech block and chamber unit in abutting engagement with the mounted barrel. j

The breech block 18 is on one side provided with a conventional extractor 106 Vand on its opposite side with a conventional ejector (not shown). The extractor 106 acts to withdraw the shell of a tired cartridge from the chamber 40 and bring it adjacent an ejection port 110 in one side of the receiver 12 (Figs. 3 and 6) during the described retraction ofthe Vbreechblock from its closed position to its open position, while the ejector throws the shell out through the port 110. The breech block 18 is 18 and the inclined Cam also manually retractible from its closed position into its open position, and the side'guide 48 is to this end provided with a finger piece 112 which extends outwardly through the ejection port 110 in the receiver 12 and is conveniently accessible thereat.

As best shown in Fig. 2, the tire-control mechanism 22 comprises a trigger 120 with a sear 122, a hammer 124 and a latch 126. The trigger 120 is pivotally mounted at 128 between spaced upright lugs 130 of a trigger plate 132 which is suitably mounted in the rear part of the recess 30 in the receiver 12 and provides the conventional trigger guard 134 (Figs. 2 and 4). The hammer 124 is also pivotally mounted at 136 between the spaced upright lugs 130 of the trigger plate 132, and is normally urged by a suitably anchored hammer spring 138 into the firing position shown in full lines in Fig. 2 in which the same strikes the firing pin 140 in the breech block 18 for firing a chambered cartridge. The latch 126 is pivoted at 128 coaxially Vof the trigger 120 and is. also located between the upright lugs 130 on the trigger plate 132. The hub 142 of the hammer 124 has a shoulder 144 which is engaged by the sear 122 on the cocked trigger 120 to hold the hammer in its cocked position shown in dot-and-dash lines in Fig. 2 in which the trigger is also shown in its cocked position in dot-and-dash lines. On pulling the cocked trigger 120 into the full-line positi-on in Fig. 2, its sear 122 will retract from the shoulder 144 on the cocked hammer 124 and release the latter for striking the firing pin 140. The link 66 of the breech block operating mechanism is longitudinally slotted as at 146 to provide clearance for the hammer 124 on its travel from cocked position into ring position, and vice versa. Under normal firing conditions, a forward end wall 148 of link 66 is so positioned that the hammer 124 engages it only after the tiring pin 140 has been struck and moved forward suciently to re cartridge c. This wall 148 also engages the hammer on the rearward movement of link 66 and swings the hammer into its cocked position against the force of its spring 138 when the breech block 18 is retracted into its open position by the hereinbefore explained recoil action of its operating mechanism 20. If the trigger 120 is released at the time the hammer 124 is thus swung into its cocked position, the shoulder 144 on the hammer will latch with the sear 122 on the trigger and the hammer will be held in its cocked position until the trigger is again pulled for ring the next chambered cartridge. However, if the trigger 120 is not released when the hammer 124 is swung into its cocked position, the spring-urged latch 126 will catch a shoulder 150 on the hammer and hold the latter against spring-return into its tiring position. When the trigger 120 is then released and forced into its cocked dot-anddash line position in Fig. 2 by the compression spring 152 between it and the latch 126, the trigger will raise the forward end 154 of the latch and thus retract the latter from interlock with the shoulder 150 on the hammer, whereupon the hammer is free to be turned by its spring 138 into the cocked dot-and-dash line position in Fig. 2 in which its shoulder 144 will be caught by the sear 122 on the trigger. Hence, even if the user of the rearm should hold the trigger 120 depressed for some time after tiring a chambered cartridge, the hammer 124 will in any event be prevented from returning to tiring position until the trigger is released and then pulled again. This is, of course, an important safety feature in the instant exemplary rearm which is of the self-loading type as will be described hereinafter.

A suitable safety 160 is provided to prevent ring of the arm. This safety 160 is, in the present instance, in the form of a pin which is axially slidable in the trigger plate 132 (Figs. 2 and 4) and has a longitudinal groove 162 which in the inoperative position of the safety is in alignment with the trigger 120 to admit the latter into its full-line release position in Fig. 2. When the pin 160 is manually shifted into its operative or safety position CII (Fig. 4), the groove 162 therein is out of alignment with the trigger and the latter is held against movement from its cocked position into its rele-ase position by the adjacent non-grooved portion 164 of the pin 160. A spring-urged plunger 166 in the trigger plate 132 may cooperate with either one of two depressions 168 in the pin 16) in order yieldingly to retain the latter either in its inoperative position or in its safety posi-tion (Fig. 4).

The firing pin is laxia'lly slidable in the breech block 18 and is normally urged by a spring 170 into the retracted position shown in Figs. 7 and 8 in which the endwall 172 of a longitudinal groove 174 in the tiring pin bears against a cross-pin 176 in the breech block. When the released hammer 124 strikes the ring pin 140 in the fashion shown in Fig. 2, the latter will be projected forwardly to tire the chambered cartridge c.

As previously mentioned, the instant exemplary tirearm is of the self-loading rtype, and the same is to that end provided with a cartridge magazine 180 and a cartridge carrier 182 which latter is actuated by the breech block 18, during an initial part of each spring-return of the -latter from its open position into its closed position, to lift a cartridge delivered from the magazine into position to be projected into the chamber 40 by the breech block on its forward travel under ,the Iurging of spring 62 into closed position. The magazine is conveniently screwed at 184 in the front wall 28 of the receiver 12 (Figs. l and 2) and holds a conventional cartridge follower 186 aand a magazine spring 188. The spring-backed follower 186 normally urges the cartridges in the magazine 180 toward and out of the opening 190. The oartridge carrier 182 is pivotal'ly mounted alt 192 (Fig. l) on the adjacent upright lug 130 of the trigger plate 132, and has a forward extension 194 which terminates in a spoon-like cartridge elevator 196 that is normally in alignment with the magazine 180 for fthe reception of a cartridge therefrom (Fig. 2). The cartridge carrier 182 has `also a rearward extension 198 (Fig. l) on which a dog 200 is pivoted as at 202. Since the construction and operation of the cartridge carrier 182 does not form any part of the present invention and is, moreover, fully shown and described in the aforementioned patent to Williams, No. 2,506,982, it is suicient for an understanding of the present invention to explain here that the breech block 18 on its rearward excursion into open po-y sition will swing the spring-urged dog 200 out of the way without tilting the cartridge carrier for the elevation of :a cartridge thereon into position for its chambering by the breech block. Thus, `the cartridge carrier 182 Will during the rearward excursion of the breech block 18 into open position remain in the position shown in Figs. l -and 2 for the reception of a cartridge from the magazine 186. Suitable provisions (not shown) may be made to control the spring-urged discharge of a cartridge from the magazine onto the carrier 182 in timed relation with the retraction of the breech block 18 into its open position, and to prevent the discharge of more than one cartridge at a time from the magazine as well as any jam of the cartridge in [the receiver during its transfer by the carrier into position for its subsequent chambering by the breech block. Provisions suitable for these purposes may be like or similar to those shown for the same purposes in the patent to Williams, No. 2,509,382, dated May 30, 1950. Soon after the breech block 18 has stanted on its spring-return from open position toward and into closed position, the same cooperates with the dog 200 in tilting the carrier 182 to raise the released cantritlge thereon into position to be pushed into the chamber 40 by the breech block during its ffurther forward travel into clos-ed position. Soon after the breech block 18 has on its travel toward closed position assumed full control over the transfer of the raised cartridge from the carrier 182 into the chamber 40, the cooperation between the breech block 18 and the dog 200 on the carrier 182 ceases and the latter is urged into its normal position regatas (Figs. 1 and 2) by the action of the spring 204. Reloading of thermagazine 188 with fresh cartridges may conveniently be undertaken when the breech block is in its closed position, by pressing the spoon-like elevator 196 of the carrier 182 inwardly, against the force of the spring 204, in order to gain access to the magazine 180 through the open bottom 32 of the receiver, :and then inserting cartridges into the magazine lagainst the forward force of the spring-urged follower 186. A conventional forestock 205 may in any suitable manner be removably mounted on the receiver 12 in'covering relation with the magazine 180. The firearm described so far may be conventional in every respect.

AsV mentioned earlier, it'is customary with firearms of this type to mount their barrels removably, with the result that prior firearms of this type could, on removal of their barrels, be red. In accordance with the present invention, firearms of this type may no longer be tired after their barrels are removed. To this end, the charnber unit 16 and breech block 18 are arranged so that they will be urged forwardly as a unit by the springurged plunger 42 from their respective firing and closed positions shown in Fig. 2 into the respective safety positions shown in Fig. 7, when the barrel 14 is removed from the receiver 12 while the breech block is in its closed position and, hence, an interlock with the chamber' unit. In order to limit-the forward motion of the chamber unit 16 and interlocked breech block 18 into the respective safety positions shown in Fig. 7 when the barrel is removed, the breech block is preferably provided with a stop surface 210 which in the safety position of the latter abuts the adjacent inner surface 212 of the front wall 28 of the receiver, but is spaced from this inner surface 212 when the breech block is in its closed or locked position (Fig. 2) when the barrel is in place. The forward shift of the chamber unit 16 and interlocked breech block 18 on removal of the barrel 14 from the receiver 12 is not participated in by the pin 46 (Fig. 7). This results from the fact, of course, that pin 46 is carried at its opposite ends in side plates or guides 48 and 50, and the latter abut against the inner surface 212 of the front wall 28 of the receiver, limiting their forward movement entirely independently of the barrel. Therefore, pin 46 `does not come to rest against the forward end 98 of slot 82 in the bolt under this condition. (See dotted line showing in Fig. 7.) There is also the further fact that abutment occurs between the collar 78 on the inertia bar 60 and the shoulder of sleeve 76 at the forward end of the latter so that the inertia bar 60 and link 66 are substantially in their most advanced positions when the breech block is in its normal battery position (Figs. 2 and 5). With the barrel removed, however, the endwall 148 of the slot 146 in the link 66 remains in the position shown in Figs. 2 and 7 and serves as a stop for the hammer 124 before the latter may strike the firing pin and fire a chambered cartridge (Fig. 7) if the hammer should intentionally or accidentally be released from its cocked position.V

While the stop 148 in the preferred illustrated form -of the invention-is formed by an endwall of the slot 146 in the link 66, it is, of course, fully within the purview of the present invention to provide a fixed stop in the receiver for the same purpose and make the slot 146 in the link 66 of any desired length as long as it provides adequate clearance for the hammer to travel into itsl firing position and return the latter into its cocked position on the rearward excursion by recoil action of the breech block 18 and its operating mechanism 20.

'The described unitary forward shift of the chamber unit 16 and interlocked breech block 18 into their respective safety positions on'removal of the barrel 14 from the receiver 12 is only possible if the breech block is in its closed position when'the barrel is removed. In that case, a cartridge already chambered before the removal of the barrel may not be fired since the hammer 124, if released'in its cocked position, will be stopped by the en dwall V148 of the slot 146 in the,V link 66 before itmay strike the tiring pin 140 and lire the cartridge (Fig. 7

It is also possible,-after the removal ofthe barrel 14 from the receiver 12, to transfer a fresh cartridge yfrom the magazine 180 into the chamber 40, by grasping the finger piece 1,12 and'retracting the breech block 18 and then releasing the latter for spring-return into its closed position. In that case, the chamber unit 16 will, immediately on release of the breechrblock 18 from interlock therewith at the start of the retraction of the latter from its closed position, be forced by its spring-urged plunger 42 forwardly from its firing positioninto a safety Y position like or similar to that shown in Fig. 8. Thecarrier 182 will during the rearward travel .of the breech block 18 receive a cartridge from the magaziner180, and will raise this cartridge into position for chambering during an initial part of the followingrforward excursion of the breech block from open into closed position. During a continuing part of this forwardV excursion `of the breech block 18 the latter will advance the transferred cartridge from the carrier 182 into the chamber 40, but this time not all the Way thereinto because the breech block, while advancing substantially to Vits normal closed position lengthwise of the receiver (Fig.` 8), fails .to follow the chamber into its safety position into which it has moved in the meantime. The reason why VVthe breech block 18 Vmay not follow the chamber 40 to its safety position lies in the fact that the substantially fully advanced breech block remains tilted about the pin 46 (Fig. 8), because the slot 92 with the lock shoulder 94 in the chamber u-nit 16 has on the aforementioned shift of the latter into safety position been brought out of cooperative relation with the key formation on the breech block so that the pin 46 is stopped from cooperating with the inclined cam lengths 88 of the slots 82 in the breech block to raise the latter into interlock with the chamber unit.` Accordingly, the breech block 18 becomes jammed, relatively lightly but nevertheless effectively, between the'rearward extension 38 of the chamber unit 16 and the pin 46 in the fashion shown in Fig. 8 and the pin 46 and the remainder of the breech block operating mechanism 20 may not advance beyond the position there shown, with Vthe result that the hammer 124, if released, will be stopped by the endwall 148 of the slot 146fin the link 66 long before it may strike the firing pin in the breech block.

The jam condition of thebreech block 18 as shown in Fig. 8 constitutes a definite safety feature to prevent the ring of therarm after the barrel is removed.` The jam condition of the breech block 18 (Fig. 8) may be remedied by forcing the chamber unit rearwardly from its illustrated safety position into its normal firing position, by remounting the barrel on the receiver, in which case the slot 92 in the chamber unit 16 will realign with the key formation 90 on the breech block and the latter will snap into interlock with the chamber unit ,by the coaction of the pin 46 and'inclined cam lengths 88 of the slots 82 in they breech block, as will be readily understood. If the chamber unit 16 is forced from its safety position back Vinto its ring position by remounting the barrel, the firearm willY then be conditioned forv immediate firing as inFig. l. However, should the chamber unit 16 be `depressed by hand from its safety position into firing position, the firearm will immediately on release of the chamber unit change to the other safe condition shown in Fig. 7 in .which both, the chamber unit 16 and interlocked breech blocklS assume the hereinbefore described safety positions. Y y Y The invention may be carried outin other specic ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the presentembodiments are, therefore, to be considered V,in all respects asV illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

What is claimed is:

l. In a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally assuming a firing position in abutment with the mounted barrel; a breech member movable in said receiver and in its closed position abutting said chamber member in its firing position, said members being yieldingly urged forwardly into abutment with each other and with the mounted barrel, and forwardly of said positions thereof onremoval of the barrel from said receiver; firing mechanism; and means rendering said firing mechanism inoperative when said members are forward of said positions thereof.

2. In a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally assuming a tiring position in abutment with the mounted barrel; a breech member movable in said receiver and in its closed position abutting said chamber member in its tiring position, said members being yieldingly urged forwardly into abutment with each other and with the mounted barrel, and forwardly of said positions thereof on removal of the barrel from said receiver; firing mechanism; and means rendering said firing mechanism inoperative when said breech member is forward of said closed position thereof.

3. VIn a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally assuming a tiring position in abutment with the mounted barrel; a breech member movable in said receiver and in its closed position abutting said chamber member in its firing position, said members being yieldingly urged forwardly into abutment with each other and with the mounted barrel, and forwardly of said positions thereof on removal of the barrel from said receiver; firing mechanism including a firing pin in said breech member and a movable hammer having an operating range to strike said firing pin; and means keeping said hammer out of striking reach of said ring pin when said breech member is forward of said closed position thereof.

4. The combination in a firearm as set forth in claim 3, in which said means is a stop in said receiver engageable by said hammer when said breech member is forward of said closed position thereof.

5. In a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally assuming a firing position in abutment with the mounted barrel; a breech member movable in said receiver and releasably interlocked in its closed position with said chamber member in its tiring position, at least one of said members being yieldingly urged forwardly from said position thereof when the barrel is removed from said receiver; firing mechanism; and means rendering said ring mechanism inoperative when said one member is forward of said position thereof.

6. In a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally assuming a ring position in abutment with the mounted barrel; a breech member movable in said receiver and releasably interlocked in its closed position with said chamber member in its firing position; means yieldingly urging said interlocked members against the mounted barrel, and forwardly of said positions thereof on removal of the barrel from said receiver; firing mechanism; and means rendering said firing mechanism inoperative when said members are forward of said positions thereof.

7. In a rearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a tiring position in abutment with the mounted barrel; a breech member movable in said receiver and releasably interlocked in its closed position with said chamber member in its firing position, said interlocked members being urged forwardly from said positions thereof on removal of the barrel from said receiver; iring mechanism; and means rendering said firing mechanism inoperative when said members are forward of said positions thereof.

8. In a firearm having a receiver and a barrel removably mounted thereon, the combination yof a -chamber member axially movable in `said receiver and normally yieldingly urged forwardly into a firing position in abutment with the mounted barrel; a breech member movable in said receiver and releasably interlocked in its closed position with said chamber member in its tiring position, said interlocked members being urged forwardly from said positions thereof on removal of the barrel from said receiver; firing mechanism including a firing pin in said breech member and a movable hammer having an operating range to strike said firing pin; and means keeping said hammer out of striking reach of .said firing pin when said breech member is forward of said closed position thereof.

9. The combination in a firearm as set forth in claim 8, in which said means -is a stop in said receiver engageable by said hammer when said breech member is forward of said closed position thereof.

10. In a `firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in lsaid receiver and normally yieldingly urged forwardly into la firing position in abutment with the mounted barrel; a breech member movable in said receiver and releasably interlocked in its closed position with said chamber member in its firing` position, said interlocked members being urged forwardly from said positions thereof on removal of the barrel from said receiver; a stop lon one of said members engageable with said receiver to limit forward motion of said members from `said positions thereof into safety positions, respectively; tiring mechanism; and means rendering said firing mechanism inoperative when said members are in said safety positions thereof.

l1. The combination in a firearm as set forth in claim l0, in which said stop is provided on said breech member.

l2. In a iirearm having `a receiver and a barrel removably mounted thereon, the combination yof `a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a tiring position in abutment with the mounted barrel; a breech member movable in said receiver and releasably interlocked in its closed position with said chamber member in its firing position, said interlocked members being urged forwardly from said positions thereof on removal of the barrel from said receiver; a stop on one of said members engageable with said receiver to limit forward motion of said members from said positions thereof into safety positions, respectively; iiring mechanism including a firing pin in said breech member and a movable hammer having an `operating range to strike said firing pin; and means keeping said hammer out of striking reach -of said firing pin when s-aid 'breech member is in `said safety position thereof.

13. The combination in a firearm las set forth in claim l2, in which said means is a stop in said receiver engageable by lsaid hammer when said breech mem-ber is forward of said closed position thereof.

14. In a firearm having a receiver and `a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a tiring position in abutment with the mounted barrel; 'a breech member movable in said receiver and interlockable in its closed position with said chamber member in its firing position; breechoperating mechanism including a link normally yieldingly urged forwardly into 'a limit position `and having 1l v with said breech member a cam-type lost-motion connection operative during forward motion of saidlink into its limit position to move said Vbreech member forwardly from an open position into its `closed position rand `cam it into interlock with said chamber memberY in its firing position,

and operative during rearward motion of said link fromV its limit position to cam said breech member from interlock with said chamber member and retract it into its open position, said lost-motion connection permitting forward motion of said breech member from its closed position relative tosaid link in its limit position, and said interlocked breech and chamber members being urged forwardly from their respective closed and tiring positions on removal of the barrel` from said receiver; tiring mechianism including ya tiring pin in said breech member 'and a movable hammer having `an yoperating range to strike said tiring pin; and a stop on said link engageable by said hammer to keep the same out of striking reach of said ring pin when said breech member is forward of its closed position.

15. In a `firearm having a receiver and a barrel removably mounted Ithereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a firing position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member in its tiring position; breechoperating mechanism including a link normally yieldingly urged forwardly into a limit position and having with said breech member a cam-type los-t-motion connection operative during forward motion of said link into its limit position to move said breech member forwardly from an open position into its closed position and cam it into interlock with said chamber member in its ring position, and operative during rearward motion lof said link from -its limit position to cam said breech member from interlock with said chamber member and retract it into its fopen position, said lost-motion connection permitting forward motion of said breech member from its closed position relative to said link in its limit position, and said interlocked breech `and chamber members being urged forwardly from their respective closed Iand tiring positions on removal of the barrel from said receiver; firing mechanism including a firing pin in said breech member and a hammer releasable from a cocked position to move Iinto striking engagement with said firing pin; and a stop on said link engaging the released hammer and returning it to its cocked posit-ion `during rearward motion of said link, and engageable by the released hammer to stop the latter out of striking reach of said tiring pin when said breech member is forward of its closed position.

16. In a rearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a firing position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member in its tiring position; breechoperating mechanism including a link normally yieldingly urged forwardly into a limit position and having with said breech member a cam-type lost-motion connection operative during forward motion of said link into its limit position to move said breech member; forwardly from an open position into its closed position andV cam it into interlock with said chamber member in its ring position, and operative during rearward motion of said link from its limit position to cam said breech member from interlock with saidchamber member and retract it into its open position, said lost-motion connection permitting forward motion of saidrbreech member from its closed position relative to said link in its limit posi-L tion, and said interlocked breech and chamber members being urged forwardly fromnth'eir respective closed and firing positions on removal of the barrel from said receiver; andY tiring mechanism including a firing pinv in said breech member and a pivoted hammer having an operating range to strike said ring pin, said link having a slot in which said hammer movefs' within its operating range and said slot having an endwall serving as Va stop engageable by saidhammcr Vto keep the same out of striking reach of said firing pin when said breech member is forward of its closed position.

17. In a firearm having a'receiver and a barrel removably mounted thereon, the combination'of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a firing position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member in its tiring position; breech operating mechanism including a link normally yieldingly urged forwardly into a limit position and having with said breech member a cam-type lost-motion connection operative during forward motion of said link into its limit position to move said breech member forwardly from an open position into its closed position and cam it into interlock with said chamber member in its firing position, and operative during rearward motion of said link from its limit position to cam said breech member from interlock with said chamber member and retract it into its open position, said lost-motion connection permitting forward motion of said breech member from its closed position relative to said link in its limit position, and said interlocked breech and chamber members being urged forwardly from their respective closed and firing positions on removal of the barrel from said receiver; and firing mechanism including a tiring pin in said breech member and a hammer releasable from a cocked position to move into striking engagement with said firing pin,

said link having a slot in which the hammer moves andV ber member axially movable in said receiver and normally yieldingly urged forwardly into a firing position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member-in its firing position; breechoperating mechanism including a link normally yieldingly urged forwardly into a limit position and a pin carried by said link and being guided in said receiver for rectilinear movement, said breech member having a cam slot receiving said pin and cooperating therewith to move said breech member forwardly from an open position into its closed position and cam it into interlock with said chamber member in its yfiring position during forward motion of said link into its limit position, and toy cam said breech member from interlock with said chamber member and retract it into its open position during rearward motion of said link from its limit position, said chamber member being urged forwardly from its firing position on removal of the barrel from said receiver so that said breech member, during forward motion toward its closed position while said chamber member is forward of its tiring position, will becomeV jammed between said pin and chamber member and said link will be stopped in an intermediate position short of said limit position thereof due to locking disalignmentof said chamber member with said breech member when the former is forward of its firing position and consequent blocked cooperation `between said pin and slot to cam said breech member into interlock with said chamber member; firing mechanism including a ring pin in said breech member and a movablehammer having an Operating rangeV to strike said tiring pin; and a stop on said link engageableY by said hammer to keep'the samel out of'striking VreachV 13' of said firing pin when said link is in said intermediate position.

19. In a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a iiring position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member in its ring position; breechoperating mechanism including a link normally yieldingly urged forwardly into a limit position and a pin carried by said link and being guided in said receiver for rectilinear movement, said breech member having a cam slot receiving said pin and cooperating therewith to move said breech member forwardly from an open position into its closed position and cam it into interlock with said chamber member in its firing position during forward motion of said link into its limit position, and to cam said breech member from interlock with said chamber member aud retract it into its open position during rearward motion of said link from its limit position, said chamber member being urged forwardly from its firing position on removal of the barrel from said receiver so that said breech member, during forward motion toward its closed position while said chamber member is forward of its tiring position, will become jammed between said pin and chamber member and said link will be stopped in an intermediate position short of said limit position thereof due to locking disalignment of said chamber member with said breech member when the former is forward of its firing position and consequent blocked cooperation between said pin and slot to ca m said breech member into interlock with said chamber member; firing mechanism including a tiring pin in said breech member and a hammer releasable from a cocked position to move into striking engagement with said ring pin; and a stop on said link engaging the released hammer and returning it to its cocked position during rearward motion of said link, and engageable by the released hammer to stop the latter out of striking reach of said ring pin when said link is in said intermediate position.

20. In a rearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a firing position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member in its firing position; breechoperating mechanism including a link normally yieldingly urged forwardly into a limit position and a pin carried by said link and being guided in said receiver for rectilinear movement, said breech member having a cam slot receiving said pin and cooperating therewith to move said -breech member forwardly from an open position into its closed position and cam it into interlock with said chamber member in its tiring position during forward motion of said link into its limit position, and to cam said breech member from interlock with said chamber member and retract it into its open position during rearward motion of said link from its limit position, said chamber member being urged forwardly from its firing position on removal of the barrel from said receiver so that said breech member, during forward motion toward its closed position while said chamber member is forward of its ring position, will become jammed between said pin and chamber member and said link will be stopped in an intermediate position short of said limit position thereof due to locking disalignment of said chamber member with said breech member when the former is forward of its firing position and consequent blocked cooperation between said pin and slot to cam said breech member into interlock with said chamber member; and ring mechanism including a tiring pin in said breech member and a pivoted hammer having an operating range to 14` strike said iiring pin, said link having a slot in which said hammer moves within its operating range and said slot having an endwall serving as a stop engageable by said hammer to keep the same out of striking reach of said firing pin when said link is in said intermediate position.

2l. In a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a tiring position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member in its firing position; breechoperating mechanism including a link normally yieldingly urged forwardly into a limit position and a pin carried by said link and being guided in said receiver for rectilinear movement, said breech member having a cam slot receiving said pin and cooperating therewith to move said breech member forwardly from an open position into its closed position and cam it into interlock with said chamber member in its firing position during forward motion of said link into its limit position, and to cam said breech member from interlock with said chamber member and retract it into its open position during rearward motion of said link from its limit position, said chamber member being urged forwardly from its firing position on removal of the barrel from said receiver so that said breech member, during forward motion toward its closed position while said chamber member is forward of its firing position, will become jammed between said pin and chamber member and said link will be stopped in an intermediate position short of said limit position thereof due to locking disalignment of said chamber mem- -ber with said breech member when the former is forward of its tiring position and consequent blocked cooperation between said pin and slot to cam said breech member into interlock with said chamber member; and firing mechanism including a firing pin in said breech member and a hammer releasable from a cocked position to move into striking engagement with said tiring pin, said link having a slot in which the hammer moves and said slot having an endwall serving as a stop engaging the released hammer and returning it to its cocked position during rearward motion of said link, and engageable by the released hammer to stop the latter out of striking reach of said firing pin when said link is in said intermediate position.

22. In a firearm having a receiver and a barrel removably mounted thereon, the combination of a chamber member axially movable in said receiver and normally yieldingly urged forwardly into a tiring position in abutment with the mounted barrel; a breech member movable in said receiver and interlockable in its closed position with said chamber member in its firing position; breechoperating mechanism including `a link normally yieldingly urged forwardly into a limit position and a pin carried by said link and being guided in said receiver for rectilinear movement, said breech member lraving a cam slot receiving said pin and cooperating therewith to move said breech member forwardly from an open position into its closed position and cam it into interlock with said chamber member in its tiring position during forward motion of said link into its limit position, and to cam said breech member from interlock with said chamber member and retract it into its open position during rearward motion of said link from its limit position, said chamber member being urged forwardly from its tiring position on removal of the barrel from said receiver so that said breech member, during forward motion toward its closed position while said chamber member is forward of its tiring position, will become jammed between said pin and chamber member and said link will be stopped in an intermediate position short of said limit position thereof due to locking disalignment of said chamber member with said breech member 1^5` 1`6` when the former is forward of its firing position and References Cited in'the le of this patent consequent blocked cooperation between said pin and l UNITED STATES PATENTS slot to'cam said breech member into interlock with said t 797,420 Feblger Aug. 15, 1905 chamber member, and nng mechamsm 1nc1ud1ng a rmg 2,476,232 Y Williams July 12, 1949 pin in said breech member and a movable hammer. 5

2,679,706 `Windle ..-June 1, 1954 

